A Triple Mushroom is an Item that has made its way into every Mario Kart game except for Super Mario Kart. It is the triple variant of the Mushroom. It is the default item in Time Trial mode.
History
Mario Kart 64
The Triple Mushroom first debuts in Mario Kart 64. This item gives you a speed boost three times the speed of a normal Mushroom. A stronger variant is the Golden Mushroom, which acts like the Triple Mushroom, except it lasts a bit longer.